1. Field of the Invention
The present invention relates to a character printing system in an electronic data processing apparatus. More specifically, the present invention relates to an improvement in a character printing system in an electronic data processing apparatus that is adapted for printing alphanumeric characters in response to numerical value coded data entered through numeral keying input means.
2. Description of the Prior Art
Of late, various data is typically processed by means of an electronic data processing apparatus. For the purpose of entry of such data, an electronic data processing apparatus is provided with a keying input means. For the purpose of entry of a variety of data, a high class electronic data processing apparatus is typically provided with a keying input means which comprises a set of keys allotted for entry of numeral characters, a set of keys allotted for entry of alphabet characters and a set of keys allotted for entry of various symbols and functions. On the other hand, a simple and inexpensive electronic data processing apparatus is often provided with a simple keying input means which comprises merely a set of keys allotted for entry of numeral characters and a set of keys allotted for various symbols and functions, while a set of keys allotted for entry of alphabet characters is dispensed with. The output data thus processed in an electronic data processing apparatus is output in a human readable form, a machine readable form, an electrical signal form, or the like. When the data is to be output in a human readable form, an output means such as a printer, a display or the like is typically utilized. Considering a case where a printer is employed, a high class electronic data processing apparatus is typically provided with a printer which is capable of printing alphabet characters as well as numeral characters and various symbols. However, a simple electronic data processing apparatus is usually provided with a printer which is capable of only numeral characters and various symbols.
A variety of types of electronic calculators are adapted for entry of numerical data by means of a numeral keying input means and adapted for performing an arithmetic operation to provide a result of operation have been proposed and put in practical use. It is often desired that such an electronic calculator be provided with a printer by way of an output means. A typical electronic calculator including a printer comprises a numeral keying input means and a printer capable of printing only numeral characters. However, it is sometimes desired in such an electronic calculator that although a keying input means is adapted for entry of only numeral characters for simplicity of structure a printer is adapted to print alphabet characters as well as numeral characters and various symbols for facility of comprehension of the output data and for providing versatility of indication of the data. To that end, an electronic calculator comprising a printer has been proposed and put in practical use wherein a keying input means is adapted for entry of numerical value coded data concerning alphanumeric characters, apart from ordinary entry of numeral characters, and a printer is adapted for printing alphabet characters as well as numeral characters and various symbols in response to the above described entries. More specifically, a convention is prepared in advance and information concerning the convention is given to the operator wherein for the purpose of entry of numerical value coded data concerning alphanumeric characters a plurality of numerical value codes of say two digits is allotted to each of the alphanumeric characters. Assuming that numerical value coding of two digits is adopted, it will be appreciated that one hundred kinds of numerical value codes are available for identification of alphanumeric characters. It is pointed out that, of these numerical value codes, several codes need be allotted for identification of various symbols and commanding information.
In some applications of such an electronic calculator having a numeral keying input means adapted for entry of numerical value codes as well as ordinary numeral characters and a printer adapted for printing alphanumeric characters in response to such entry, it is further desired that two or more kinds of alphabet characters, such as upper case type alphabet characters and lower case type alphabet characters, or English alphabet characters and Japanese kana characters, or the like can be selectively printed. However, this increases the number of characters being printed and accordingly increases the number of numerical value codes. Thus, it could happen that each numerical value code need be constituted of say three digits rather than two digits as discussed in the above. Such an increased number of characters being printed and an increased number of digits to be allotted for each numerical value code make more complicated the structure of the required circuitry and also make more complicated a manual entering operation by an operator of numerical value codes. Hence, it is desired that there is provided an electronic data processing apparatus having a numeral keying input means adapted for entry of numerical value codes as well as ordinary numeral characters and a printer adapted for printing alphanumeric characters in response to such entry, wherein numerical value codes for two or more kinds of language characters can be entered with a simplified structure and entry operation.